Propylene glycol oral liquids

Protease Inhibitors (Pis) Amprenavir 7.1-10.6 h Chronic Dysllpidemias, insulin resistance (diabetes mellitus), hepatotoxicity, lipodystrophy osteoporosis. Diarrhea, nausea, perioral/oral paresthesias, rash. Liquid product contains propylene glycol. ... 

The sponge phase has the same visual appearance as the microemulsion phase, i.e., an isotropic liquid, but it differs from the latter in the way the emulsifier molecules are organized in the system. In a microemulsion the emulsifier forms a monolayer at the oil/water interface, which makes it possible to create systems with high amounts of oil and water if the emulsifier system is well balanced. In a sponge phase, the emulsifier forms a bilayer (normal or reversed), which will limit the incorporation of both oil and water. Although propylene glycol is not a food additive (however, it is used in oral pharmaceutical formulations), we find it relevant to mention it in this context, since it aids in the formation of many different types of phases [14]. 

Water supports the growth of micro-organisms, therefore oral aqueous solutions, suspensions, emulsions and solubilisates in multidose containers should be preserved. Preservatives may be used for that purpose as well as excipients with preservative properties, such as propylene glycol. See Sect. 23.8 for extensive information on preservatives. Table 5.18 summarises preservatives with properties especially relevant for oral liquids. 

In many oral liquids the preservative methylparaben is used. Its dissolution rate can be increased by heating or by using concentrated solutions in organic solvents such as propylene glycol (see also Sect. 23.8.5). 

When saliva production is insufficient, many different liquids can be used. They vary from glycerol with citric acid to the saliva substitutes already mentioned in Sect. 7.1. Citric acid stimulates the saliva production in the salivary glands, and therefore raises the amount of saliva in the mouth. If there is damage to the oral mucosa, it is best to avoid ethanol and propylene glycol, because these solvents may cause irritation, A German hospital developed an... 

The pH is important for the preservative effect of sorbic acid and parahydroxybenzoic acid esters. These substances are most effective at pH <5. Since sorbic acid decomposes faster at low pH, pH 5 is used as a compromise (see Sect. 23.8.6). At a pH above 5.5-6.0, sorbic acid is not effective at all. At pH 7-8.5, the effectiveness of the parahydroxybenzoic acid esters is strongly reduced, in part due to their chemical instability. This implies that for dermatological preparations with a pH > 7, or in case of hypersensitivity for parahydroxybenzoic acid esters already > 5, the pharmacist has to resort to propylene glycol or probably phenoxyethanol. In case of an oral liquid with such a pH,... 

Propylene glycol is commonly used to solubilize drugs in topical, oral, and injectable medications. Cardiac arrhythmias, CNS depression, and seizures have been reported in children who have ingested liquid medications containing propylene glycol, and... 

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